Conventionally, there has been known a so-called autonomous-traveling type vacuum cleaner (cleaning robot) which autonomously travels on and cleans a cleaning-object surface while detecting an obstacle or the like by using a sensor or the like as an example. In such a vacuum cleaner, in a lower part of the vacuum cleaner's main casing where a dust collecting unit or the like are provided, a cleaning unit provided with a suction port communicating with the dust collecting unit is formed, and moreover a pair of driving wheels is attached to make the main casing autonomously travel. Also, an electric blower is housed inside the main casing, and a suction side of the electric blower is communicated with the dust collecting unit. Then, as the electric blower is driven, dust and dirt are sucked along with air via the suction port into the dust collecting unit, thus cleaning.
With such a vacuum cleaner as described above, there are some cases where the cleaning unit is made up/down movable relative to the main casing so as not to catch on any step gap of the cleaning-object surface or the like. Accordingly, there is a need to prevent any impairment of the communication between the suction port and the dust collecting unit during such up/down movement of the cleaning unit.